


Black Room

by Ceffyl_Dwr



Category: Granblue, Granblue Fantasy (Video Game)
Genre: Degradation, Dirty Talk, F/M, Lucilius has a nasty mouth, Reader is an unwilling test subject, Sex and Philosophy, blowjob
Language: English
Status: Completed
Published: 2020-06-06
Updated: 2020-06-06
Packaged: 2021-03-03 23:02:30
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 3,676
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/24563560
Author URL: https://archiveofourown.org/users/Ceffyl_Dwr/pseuds/Ceffyl_Dwr
Summary: Lucilius has a probably very much illegal lab and he tries to make his girlfriend his assistant.orLucilius is good a dirty talk and Reader gets off on it.
Relationships: Lucilius (Granblue Fantasy)/Reader
Comments: 1
Kudos: 30





	Black Room

**Author's Note:**

> This is primarily sex, in a weird room with a bit of philosophy. In my head Lucilius would be an anarchist so in this modern AU he is! Reader is his longtime lover. Lucilius is probably into illegal shit too.
> 
> Lucilius is degrading and has a nasty tongue and likes to use it and reader likes it when he uses it. Lucilius also likes it when reader uses hers~

“No, no, no.” You denied.

Lucilius gave you a nonplussed look. “Are you done throwing a fit?”

“No! That’s just...no! I will not!” You continued.

“You’re being unreasonable.” He argued.

You glared at him. “You injected your own brother with an unknown untested substance! All because he was right there as your assistant!”

He shrugged. “It’s just Belial, he’s probably injected much worse.”

“How do I know you won’t do that to me?” You demanded, still glaring.

“Because you aren’t Belial who is useful for very few things, one of which is being a test subject.” He explained. “Also, you can actually say the words’ no’. Belial is absolutely incapable of saying no to anything I do, why not take advantage?”

You hated that his words made a twisted sort of sense. “You are telling me that if Belial told you no, you wouldn’t do it?”

He barked out a harsh laugh. “It’s Belial, thinking about such an impossibility is a waste of my time.” He started to descend the stairs before them. “Mask, coat, and gloves.”

“Give me some insurance that you won’t use me as a test subject.” You insisted, not moving an inch.

He sighed. “Why would I want to possibly damage the only person I consider a decent fuck?” With a shake of his head he disappeared into the darkness of the basement.

You blushed at his blunt language. “That is not true and you know it!” You shouted before grabbing a white lab coat and putting on the gloves and mask and hurrying after him.

The basement of the Providence house contained one of the best maintained, thoroughly stocked, cutting edge laboratories outside of those the military didn’t want the public to know about. Lucilius would know, he had taken a few instruments from a couple such bases using less than savory connections. For all intents and purposes this lab didn’t exist and he wanted it to stay that way. He didn’t need the military tracking him down, he’d had more than enough recruitment letters as it was. If they knew what he was actually capable of they’d never leave him alone.

With a disturbing ease, Lucilius weaved through the benches, flicking various switches and recording readouts. You caught up to him and resumed glaring.

“That was a lie.” You muttered.

He scribbled down a few notes regarding impurities on the latest samples of some no doubt illegal experiment while addressing your concern. “Somewhat. You have a tight hole and a smart mouth. The only people who actually care to fuck me are loose as hell or never shut up about the most inane subjects.”

Your blush deepened. “T-that...is disgusting.”

He snickered under his breath and added a little more acid to a biuret. “What’s truly disgusting is how much people think others want to hear about their idiotic opinions about everything on television, or how they outright imply that they could fix all the world’s problems.” He scribbled down a few more notes as four connected screens started to generate every manner of chart. “Ugh, Belial’s been down here. I hate it when he tries to chart every reaction. It’s information overload and most of it is inconsequential garbage anyways.” He turned to you. “Could you fix this so it displays these readouts?”

You took the list he handed you and nodded. “Yeah.”

He nodded. “Good. Find me when you’re done.”

Messing with the program took barely any time, you had done this before, so the majority of it was spent trying to track Lucilius down. He had several rooms with almost zero visibility and navigating the maze of benches was no small feat. Still you managed to find him in the corner of a narrow hallway grabbing a few more flasks which he quickly handed to you.

“Very good. Take these and follow me.” He instructed.

“Fine, just remember I am not a test subject.” You warned.

He grunted and once again took off through the maze, stopping at what for all the world looked like a glass rube goldberg machine. “ Match the colors, one for each level.” He muttered as he ducked down and started opening up the gas tanks. “Don’t breathe deep for two minutes. The tubes seem close to cracking. Remind me to flog Belial for his incompetent maintenance.”

You sighed. “One or two tubes through the whole lab? That deserves such harsh treatment?”

He stood up and closed the cabinet doors before grabbing his tongs. “Not entirely, but he also left his latest conquest’s underwear on the couch again.” He shook his head. “His maintenance, while not perfect, is better than most I could get. But fucking on the couch? Disgusting.”

You nodded with a grimace. “Okay, that’s disgusting I agree.”

“Speaking of fucking, are you free after this reaches the correct pressure? It’ll take about 2 hours to run and I’m bored.” He asked.

“Really?! Did you want me to come over because you were...excited?” You asked with another grimace.

“Not really, just seeing you in lab gear is doing it for me.” He responded with a small nasty smirk. “So, since the couch is infected, how about the kitchen countertop? “

“You have no shame.” You replied with a shake of your head.

“Of course, shame is useless.” He countered. “So, the countertop? Or are we just going to do it here?”

You looked around. “The countertop is too open so-!”

Before you could finish he had grabbed your arm and pushed you into an unlit room. Even with your excellent night vision you were still practically blind. With a squeak of protest you groped around in the darkness for him but he was gone.

“Lu-Lucilius! Get back here!” You shouted, panic starting to set in. “You promised I wouldn’t be a test subject!”

“I lied.” He snickered as you felt something sharp poke you and the telltale pinch of being injected with something.

“You, you are a-” You began but he silenced you with a messy kiss.

“Calm down. It’ll just allow you to experience the Black Room better.” He explained, ducking an errant swing of your fist. “If it helps Belial and I figured this out early last week so it’s tested and has no adverse side-effects.”

“You still injected me without telling me what it was!” You hissed, trying to find your way to the door but having little success.

“I told you what it was, just in a different order.” He halfheartedly defended.

You yelped as he wrapped his hands around your sides and pulled you down. Unceremoniously you fell backwards, knocking into him much harder than he was expecting. You smirked in vindication as he grunted and groaned in pain.

“Stop squirming, gah, just stay still. No more injections, promise.” He hissed, relaxing his grip and nestling your backside against his groin. “There, now you can wriggle if you just can’t calm the fuck down.”

With a deep breath you tried to push all of your weight back to squish him but immediately lost your fighting spirit as he bucked, rubbing his quickly hardening bulge on you. With a whining noise you sat up and tried to scoot away.

“Oh don’t act like you don’t like it.” He muttered, slapping your butt. “If it bothers you so much why don’t you turn around? The enhancer should be kicking in.”

“Enhancer?” You wondered aloud, pausing long enough to realize that your dark vision was working but not in a way you were expecting. 

The darkness, instead of tinting everything, was instead like water but it only stuck to the walls, floor, and ceiling. Occasionally what looked like a black mist would pass by but it disappeared quickly enough. Slowly you turned around and realized that you could see pretty much every detail of Lucilius even though everything else was covered in the strange darkness.

“The paint in this room contains a contaminant that I initially introduced in order to make black light more intense however it did something else. Still haven’t figured out what reaction is occurring but it’s relaxing to be in.” He explained.

You blinked and continued to look around before your gaze settled back on him. “ Well, if it’s harmless. There aren’t any noxious fumes?”

He gave you a skeptical look. “Would I subject myself to danger?”

“Alright.” You acquiesced. “It’s definitely unique.”

“Like the world is gone and this is all that’s left. No rules, just an endless expanse. Or maybe the world never was and this is just existence. “ He mused. “It’s freeing.”

“I could see how you feel that way. It’s fairly...worrying for me. It’s just...there. Like you said, no rules, what am I supposed to do?” You said, feeling a little nervous.

He smirked. “Fuck like nobody’s looking? Like there have never been any rules about how it’s supposed to be done?”

“Of course you bring it back to that. You are really horny today.” You noted with an exaggerated sigh as he bucked against you again, the friction shooting pleasurable sparks up your spine.

“You, in a lab coat, the rest of the world gone and all its boundaries with it, ultimate freedom. How could I not be horny?” He countered with a pleased look. “Now strip.”

“But I thought you liked the lab coat?” You teased.

“I do, so you’ll be wearing it naked.” He nonchalantly replied, his voice rising an octave as you started shifting around taking off your clothes. “Hm, get off before you start stripping, I need to take off my pants and your hips are in the way.”

“You have such a way with words.” You teased again but did as he said.

“Ah right, you get off on being verbally degraded.” He teased back. “ Here I’ll rephrase; stop grinding on my lap and strip for me like the degenerate you are.”

Hearing his cruel words in such a deadpanned tone made your toes curl. “ That is so rude, I am not a degenerate.” You shot back. “I will strip however I please.”

“No, you will strip however I please. Fortunately for you I enjoy seeing the naked expanse of your skin so you don’t have to get on your knees and wiggle your ass in order to entice me, beastly creature that you are.” He demanded. “Now hurry up, my cock is starting to get cold.”

With a blush and an exaggerated sight you took off the lab coat and tossed it to him so you didn’t lose it amongst the inky blackness that pervaded everything except yourself and him. He caught it and draped it over the back of the cushy swivel chair he was sitting in. His eyes narrowed in anticipation and his cock stood at full attention in appreciation of your naked form. You took off your clothes as quickly as possible, kicking them over to the side. He threw the coat back over to you and you put it on, keeping the front open to expose your entire front.

“Even from here I can see you’re dripping.” He commented. “Penetrate yourself on my cock, I want to see you moan and writhe.”

You scowled. “Disgusting.”

“Are you seriously going to play hard to get even though I fucked you on the northwest lab wall, titration bench #6, my bed, your bed, your closet, and the lab entrance?” He asked scathingly.

“Those are your fault!” You hissed.

“Shirking off responsibility? Pathetic. Or is it just that you’re every bit the bitch that you look like? An animal in heat, rutting against anything they can find? Mindless, searching for pleasure anywhere they can find it?” Animals can’t assume responsibility, that must be your mindset.” He began to ramble, insulting you at every turn.

Your nostrils flared in indignation and a fire burned in your chest. “I’m the animal? You couldn’t keep it in your pants half the time which is why we ended up in all those places!”

He sighed and beckoned you forward. “I never said I wasn’t. I’m a creature with a drive to procreate as are you. The difference between us is that I fully embrace this, I take responsibility for my desires. I’ll also take responsibility for yours too, which is what you want.”

You walked closer to him and crossed your arms over your breasts, squishing them together. “I...acknowledge my desires...I just also have-”

He cut you off by leaning over and grabbing your arm. “Enough useless chatter. You can babble more once you’re bouncing on my lap.”

You gasped and tried to defend yourself but he smashed their lips together and tugged you down until you were straddling his hips. He aggressively bit at your lips until he drew blood and then licked it away. He smirked as he looked at your sweaty face, eyes angry and hazy with lust, lips shining and red.

“Animal.” You snapped as you licked your sore lips.

“Look around you, we’re in a place where there is nothing. No labels such as animal, human, robot, we simply are. No labels, no rules.” He told you, going off into another tangent. “Before you spout some nonsense like, ‘you called me an animal.’ I was just doing that to get you wet. As I said…” He paused and grabbed your chin, moving your head side to side as though inspecting you. “...you like being treated like an animal.”

Seeing that you were going to lose the fight if you continued to play defensively, you changed your tactics. “And you like debasing and degrading me. You like treating me like cattle or a prized dog. You...get off...on taking away my humanity.”

He raised an eyebrow. “So you noticed. “ He responded sarcastically. “So, now that we’ve stripped off the thin veneer of modesty, shame, and everything that society has imposed upon us, are you ready to indulge in anything and everything however we want it with no fear or shame? Blaze our own path?”

You snickered. “Blaze our own path? We’re going to be screwing that’s like the most base of desires, the oldest most worn path ever.”

“Oldest most worn path? Hah!” He bitterly laughed. “It is an old path in that it is ingrained into humans. However, the act and execution of sexual copulation is extremely diverse. As long as you fuck according to your own desires and purposes, in ways that define you, then you’re blazing a new path.” 

You ground down on his cock, both of your laps slippery with arousal. “No shame hm? Do it then, make me feel no shame.”

He sighed with a grin. “Make me do all the work? Lazy.”

Despite his whining he eagerly reached down and coated his fingers in the fluids. Slowly he teased his fingertips around your folds, tracing their shape. He could feel you quivering against him, fighting the impulse to buck needily into his hand. Abruptly his other hand shot out and wrapped itself around your neck. You gasped and immediately clawed at his hand but stopped short as his fingers entered you and scratched against your inner walls. Caught off guard your hips plunged down, engulfing two of his fingers up to the knuckle as a wave of lust crashed into you.

“Gah, y-!” You cried out as he released his grip on your neck and replaced it with his teeth. “That was unfair...oh...ohh…” You moaned.

“You make me do all the work and say that I’m being unfair? Aren't you ungrateful.” He put his hands on your shoulders and pushed you down. “Get on your knees.”

You glared at him but let him push you down between his legs. Your knees touched the floor which had the sensation of a hard surface but looked as though it went on forever. You blinked as you looked down into an inky black nothingness. The discrepancy tugged at the back of your mind but you were broken out of your trance like state by his cock poking insistently at your cheek.

“Suck it. If you’re going to spout nothing but ungratefulness then at least use me to muffle yourself.” He commanded, spreading his legs further and leaning back.

You resisted the urge to nip his cock head for good measure but you remembered the last time you had done that and listening to him rave and rant for the next thirty minutes was not something you cared to repeat. Cautiously you licked the tip and made your way down the shaft. Your tongue traced the veins, made even more pronounced by the inky blackness below them outlining his straining cock.

“Damn you’re good.” He muttered.

You felt a bit of pride at his compliment, taking him halfway into her mouth, sucking lightly. He groaned and weakly thrust forward edging himself further into your mouth. As the wet heat enveloped his shaft he grit his teeth and tensed.

“Tease, take it all.” He ordered but his words were higher pitched.

His eyes closed tightly as he sunk his fingers into your mess of hair and forced you to deepthroat him. Had this been anybody else he would be risking a gag reflex causing his partner to vomit all over his lap but this was his girlfriend of ten years. You had no gag reflex amazingly and so you could deepthroat him from dawn to dusk and never gag as long as you knew what was coming. He moaned again as he felt your lips touch the base of your cock, your hot breath on his heavy balls.

You squirmed but took him, easing your throat as the thickest part of his shaft stuffed itself deeper inside. He let out a strangled gasp as you swallowed and your throat constricted around him. Ecstasy flooded him and he fought the urge to come.

“Get...Off…!” He bit out.

It took a bit of maneuvering but you managed to pull away, sliding the pulsing cock out of your mouth without accidentally biting. Your teeth grazed the top and bottom, catching on the ridge of his cock head and he nearly came, hunching over and digging his nails into your scalp. You yipped and opened your mouth wider, panting as the tip of his cock left your mouth.

“Good, good. Now ride my cock, ride me until I fill you up and you come all over my lap.” He demanded. “I know you want this, chase it, fight for it, free yourself and let go!”

His words were finally getting to you. You wanted what he was talking about. Body flushed with heat, you shakily climbed back onto his lap. Gingerly you gripped his cock and lined it up with your entrance. You cried out as the tip of his cockhead nestled between your folds, begging entrance. Before you could sink down onto him he bucked upwards with a surprising amount of force.

“Y-you said to free myself…” You panted.

“I did, but I never said I couldn’t do the same.” He countered with a nasty grin.

You gave him a grin of your own, rising to his challenge. “Fine then.”

As he bucked again you spread your legs wider, taking him in and forcing him deeper as both of your hips meet with a force that pushed him back into his chair causing it to creak loudly. The both of you moaned loudly, gripping each other before losing yourselves to the pressure and friction. You ground against him until you were sure you’d chafe your inner walls and he thrust upward until his hip muscles were crying out with pain from the strain. Their sweaty bodies slapped together and the wet sounds of their arousal filled the room, echoing off walls that couldn’t be seen.

“Join me, in creating a world of true freedom. Abolish all rules, all constraints, make your choices and don’t let anyone control you!” He bellowed with much more force than his small body implied.

“Yes!” You replied with excitement and anticipation. “True freedom!” You shouted back, sending him over the edge.

He bit into your shoulder as he came hard. Your vision went white as you felt the unbearable pressure coiled in your belly break and send shockwaves throughout your body. You came just as hard, your walls clamping down on him in an almost vice like grip. He continued thrusting but with much less force, letting you milk him. His body relaxed once he was spent, basking in the afterglow.

“So...how much of that was truth...and how much of that...was what I wanted...to hear?” He asked between pants as he tried to catch his breath.

“I...love you...and I want freedom...I’m not into all your...anarchy...but I would like to be free of the constraints.” You replied, having just as much trouble trying to catch your breath.

“Hm, I’ll take it.” He said breathily. “You’re enough of an individual that it works for you.”

“You’d hate if I just followed you because I love you.” You added.

“You do understand me.” He noted fondly, kissing the bite he’d left on your shoulder.

You hissed at the sting of the puncture from his teeth. “It’s why I love you. This is so wrong, what is wrong with me.”

“Everything.” He whispered before kissing you lightly. “ Now shut up for the next hour, I need to rest before it’s time to check the experiment.”

“So romantic.” You mustered sarcastically.

He mumbled something unintelligible before nuzzling into your shoulder.

“When does this wear off?” You asked, suddenly realizing you had no idea how to even get out of this space of inky black.

He groaned. “One hour, now shut up and let me enjoy your body in peace and quiet.”

You sighed but fell silent and made yourself as comfortable as you could. 

“Love you.” He whispered, quite possibly in his sleep as his breathing had already fallen into a typical slow rhythm.

You didn’t question it and instead smiled before resting your head against his.


End file.
